Chosen Solution
Hi all, first, THANKS for what you guys do here!!! I’m not even sure how to ask this. I have multiple usb sticks and external USB HD (think of Seagate FreeAgent GoFlex), they all work in my other MacBook Pro (High Sierra, if it matters) or any other Windows machine. (the MacBook Pro at least recognize and acknowledge them) The problem I’m having is with this other MacBook Pro 15" (non-retina, mid 2012 also on High Sierra). I plug in the External HD and it would work fine. but when I plug in the USB sticks it does nothing. Does not light up to signal power, does not show up in disk utility, nothing. I would assume if the USB ports had power issues, the external HD would not be read neither, but thats not the case. USB Sticks - Nothing. External HD ok. I did the SMC and RAM reset multiple times already. Thank you in advance!
Sounds like the USB ports power feeds are not working. You’ll need this tool to check things: USB Mini Voltmeter. If thats the case your logic board needs fixing which is beyond most DIY’er’s. Your other option is replace the logic board.
